During an interview, Jessica brought up Krystal, saying, "She's like a friend. Soo Jung is mature so we talk a lot. It's hard to meet a true friend in society and have sincere conversations, but since Soo Jung is my family we've become most the dependable colleagues and friends."
Jessica, who was then asked if she was aware of her sister's relationship with Kai, answered, "Of course I knew. I gave her advice and told her to be careful about exposing it to the public."